BIO Chapter 9: Cellular Respiration

dehydrogenations

lost electrons are accompanied by hydrogen ions.

oxidation

loss of electrons making bond positive

autotrophs

make their own organic molecules through photosynthesis

heterotrophs

live on organism compounds made by other organisms.

reduction

gain of electron making bond negative.

substrate-level phosphorylation

metabolic reactions that creates ATP by an enzyme transferring a phosphate group from a substrate to ADP.

oxidative phosphorylation

Last stage of cellular respiration, that uses oxygen and electrical transport chains to make ATP.

ATP hydrolysis drives endergonic reactions through..

energy coupling and phosphorlaytion

energy coupling

cells use energy released by exergonic reaction to power endergonic reaction.

Phosphorylaytion

Addition of a phosphate group to an organic molecule or protein changing its activity, stability, or energy state.

stages of cellular respiration

glycolysis, pyruvate oxidation, acid citric cycle, oxidative phosphorylation.

glycolysis

in the cytoplasm, break down glucose into two molecules of pyruvate,

pyruvate oxidation

complete the breakdown of glucose, converting 3-carbon pyruvate into 2 carbon acetyl-CoA

Acetyl-CoA

central metabolic molecule that delivers acetyl groups into the citric acid cycle to help cell produce energy.

Citric acid cycle

Complete the breakdown of glucose, releasing stored energy through oxidation of acetyl-CoA.

chemiosmosis

movement of ions across a semipermeable membrane down their electrochemical gradient to make ATP.

electron transfer chain

series of protein complexes and mobile molecules that transfer electrons and pump protons to generate ATP

Evolutionary significance of glycosis

performed without oxygen implying it was evolved before oxygen.

Endergonic reaction

reaction requiring input of energy (non-spontaneous ). Positive G (free energy)

exergonic reaction

reaction that release free energy (spontaneous), Negative G (free energy)

aerobic respiration

consumes oxygen and organic molecules breaking down glucose and turning it into ATP.

anaerobic respiration

similar to aerobic respiration but without using molecular oxygen.

cellular series of reactions

oxidation, dehydrogenations (all equaling to a loss of hydrogen atom)

NAD+ to NADH

NAD+ + 2 electrons + 1 proton (reversible)

NADH function

passes electrons to the electron transport chain

where does reduction take place in cellular respiration

across the cytosol (cytoplasm) and mitochondria

where does oxidation take place in cellular respiration

glycolysis, pyruvate oxidation, acid citric cycle, oxidative phosphorylation. (everywhere)

how does ATP power cellular work

primary energy currency, like rechargeable battery.

energy investment phase

Cell consumes 2 ATP molecules to phosphorylate and destabilize glucose preparing to split it into two 3-carbon sugars.

Energy payoff phase

cell harvests energy by converting the two 3-carbon sugars into pyruvate

glucose to pyruvate general concept

each step has an enzyme with a catabolic reaction

catabolic reaction

metabolic process breaking down large, complex molecules into smaller simpler units while releasing energy.

pyruvate

3-carbon organic molecule serving as a central hub for cellular energy metabolism (end-product of glycolysis).

what does glycolysis produce?

2 ATP molecules, 2 NADH molecules, 2 pyruvate

What does pyruvate oxidation produce?

1 CO2, 1 NADH, 1 acetyl-CoA

What does citric acid cycle produce?

1 ATP, 3 NADH, 1 FADH2, (per turn)

how many electrons are stored in NADH?

two

fermentation

when oxygen is not available organic molecule is the final electron acceptor.

Which form of oxidation of NADH produce more ATP

Aerobic respiration

what happens to pyruvate in glycolysis if oxygen is present?

undergoes aerobic respiration

what happens to pyruvate in glycolysis if oxygen is not present?

undergoes fermentation

first step of citric acid cycle

acetyl-COA + oxaloacetate = citrate

what do both NADH and FADH2 do

donate electrons to the electron transport chain, powering ATP synthesis.

What does the energy lost moving down the energy transport chain do?

pump protons across membrane.

proton gradient

electrochemical difference in hydrogen ion concentration and charge across a biological membrane that stores potential energy for cellular work.

final electron acceptor in aerobic cellular respiration is..

oxygen

ATP synthesis

membrane bound enzyme that uses the energy of the proton gradient to synthesize ATP from ADP + P

what is the immediate protein source for the production of glucose?

proton gradient

how do protons make ATP

through spinning across a turbine converting electrochemical energy into chemical energy

what does anaerobic respiration do that fermentation does not?

break down glucose

whats the purpose of fermentation

to allow cells and microorganisms to generate ATP without oxygen

ethanol fermentation

occurs in yeast

lactic acid fermentation

occurs in animal cells

deanimation

removes the nitrogen-containing amino group (-NH₂) from an amino acid so the remaining carbon skeleton can be used for energy

catabolism of protein

the metabolic breakdown of proteins into smaller polypeptides, peptides, and individual amino acids

what happens to remainder of protein catabolism?

Is converted to molecule that enters aerobic respiration

Catabolism of Fat

fatty acids converted to acetyl groups by b - oxidation to release energy when in demand

beta - oxidation

the metabolic process that breaks down fatty acid molecules to generate acetyl-CoA, NADH, and FADH₂ for cellular energy

Alpha - oxidation

the metabolic process that breaks down fatty acid molecules to generate acetyl-CoA, NADH, and FADH₂ for cellular energy

lactic acid fermentation

occurs in animal cells, produces lactic acid

Ethanol fermentation

anaerobic biochemical process that converts sugars into ethanol and carbon dioxide using yeast or other microorganisms

Ethanol fermentation produces

Co2, ethanol, NAD+

enthalpy

chemical energy of a molecule

fermentation purpose

to regenerate NAD+ from NADH without oxygen so that cellular energy production (glycolysis) can keep running

allosterically

a regulatory mechanism where a molecule binds to a protein to a site distinct from its active site, causing a physical shape change that alters the protein's activity

ATP synthase

Membrane bound enzyme that uses the energy of the proton gradient to synthesize ATP from ADP + P.

proton gradient

electrochemical difference in hydrogen ion concentration across a biological membrane

whats the immediate protein source for the production of glucose

proton gradient

chemiosmosis

the use of energy in a H+ gradient to drive cellular work

citric acid cycle product yield

3 NADH, 1 FADH2, 1 ATP, 2 Co2, 1 oxaloacetate molecule.

pyruvate dehydrogenase

catalyzes 3 reactions:

oxidation of pyruvate and release of Co2

reduction of NAD+

two-carbon fragment + coenzyme A = acetyl CoA

pyruvate oxidation product

1 Co2, 1 NADH, 1 acetyl - CoA

autotrophs

able to produce their own organic molecules through photosynthesis